If accepted by the community, an ontology could easily be built using the currently provided URI's

?

Distinguishes (for example) a class of proteins from the document describing the class of proteins

yes

in principle

in principle

yes

yes

Encourages re-use of URIs by independent parties (e.g. URIs do not 'look' proprietary)

Probably yes. PURLs appear to some to be independent and stable.

It is the intention that LSIDs are re-used by third parties, and there is a part of the specification describing how third-parties can register themselves with the primary authority such that they can be discovered during resolution. The reliance on a primary authority to always be available may be just as practical a problem as other urn based schemes though.

URIs contain "bio2rdf", although the functionality of the URI does not rely on the http://bio2rdf.org section. May seem more unstable than a urn based proposal which seems on the surface to be more clearly planned out

Resolution to data provides whatever document format was intended by the provider of the identified "thing". Resolution to metadata (may) provide other LSIDs pointing to the same information in other formats.

Yes. Linked to original document when available. Resulting document is RDF with clear links to any other representations without further negotiation.

Uses content-type negotiation to decide on whether to forward to a web page or a machine readable representation.

Capture document contracts (e.g. stability, permanence)

Assumes users will cache documents if they want a guarantee, as most of the data is dynamically generated from providers on demand.

no

Support for versioning (of what exactly?)

Promise of bitstream identity (or nothing) for whatever is returned by the getData resolution method. No versioning of metadata associated with the same LSID. This is useful for when LSIDs are used to identify documents or records. There is no explicit semantics however on the version identifier other than that it is different to another one.

Rely on upstream providers to version their information, which is then reflected in a different identifier, possibly with a relationship to previous versions if indicated by providers.

Version numbers may appear as part of identifiers, but there is no explicit support.

Provide for cases where data is available in a structured, but not semantically enhanced format

Based on RDFizers, which may utilise RDF where available but do not rely on providers changing their systems to be able to utilise and integrate the information into the ultimate semantic web goal

(add others)

Discussion of this matrix

I think "Encourages re-use of URIs by independent parties" is the most important feature of all, although it is largely neglected. Many entities are not re-used by other ontologies simply because of their namespace. (MatthiasSamwald)

It should at least mean that discovery is not painful, as this is where the effort barrier to "encouraging re-use" will be broken. Neutral branding isn't as important in my opinion as it doesn't give the impression that the ontology is accountable to a certain organisation. PeterAnsell

RDFa is not integrated in the current proposals [JAR answers: because RDFa has to do with the representation of RDF; syntax is independent of URI choice]

SPARQL endpoints are not integrated in the current proposals [JAR answers: URI choice potentially affects every context of use, and there is nothing special about SPARQL as far as I know]

The main difficulties I have with this matrix are:

It is not comparing apples to apples. For example, "W3C TAG Recommendation" is very broad, and presumably would encompass (nearly?) all of the other proposals, whereas LSID is very specific. Another example: PURLs are a technique that can be used in conjunction with many other techniques. Also, a 303-redirect service can be used with other techniques.

It is not clear what some of the column titles mean. For example, does "W3C TAG Recommendation" imply the use of HTTP URIs?

The wiki markup for it is quite difficult to edit. Does anybody have suggestions for easier editing?

With that said, this matrix may be helpful in thinking things through, even if it is insufficient for direct decision-making. -- DBooth